The present disclosure relates, in various embodiments, to thin-film transistors (TFTs) comprising a semiconducting layer and a gate dielectric layer comprising a block copolymer. The block copolymer comprises a polar block and a nonpolar block. The resulting dielectric layer has good adhesion to gate electrode of the TFTs and good compatibility with the semiconducting layer. Methods for making and using the same are also disclosed.
There is interest in organic thin film transistors (OTFTs) for applications such as radio frequency identification (RFID) tags and backplane switching circuits for displays, such as signage, readers, and liquid crystal displays, where high switching speeds and/or high density are not essential. OTFTs may be made using low-cost solution or liquid fabrication techniques. They also have attractive mechanical properties such as being physically compact, lightweight, and flexible.
OTFTs are generally composed of, on a substrate, an electrically conductive gate electrode, source and drain electrodes, an electrically insulating gate dielectric layer which separate the gate electrode from the source and drain electrodes, and a semiconducting layer which is in contact with the gate dielectric layer and bridges the source and drain electrodes. Their performance can be determined by the field effect mobility and the current on/off ratio. High mobility and high on/off ratio are desired.
Materials useful in electrically insulating gate dielectric layers should have low leakage current, good adhesion to the gate electrode, good compatibility with the semiconducting layer, etc.